Electrically controlled brake



Dec. 22,1936. R. l.. NASH ,ELECTRIQALLY CONTROLLED BRAKE Fi'led May 9, 1934 INVENTOR. RICHARD L NASH i. Wm

A TTORNEY.' Z

Patented Dec. 22, 1936 UNETED STATES PATENT OFFICE ELECTRICALLY CONTROLLED BRAKE Application May 9, 1934, Serial No. 724,739

'I Claims.

This invention relates to braking systems, such as employed on trains, and has particular relation to electrically controlled brake systems.

It is an object of my invention to provide means Vwhereby the operation of one electro-responsive ldevice employed in effecting the operation of the brakes aiects or controls the operation of another brake operating electro-responsive device.

Other objects of my invention will be made apparent in the subsequent description of one embodiment thereof when read in connection with the accompanying drawing wherein the single gure is a diagrammatic view of the equipment for one car, partly in section and taken together with the control device disposed on another car or on a locomotive, the system being shown in the normal or running and release position.

It will be understood that equipment similar to that to be described for one car is also provided on the other cars and that the equipment on all the cars functions in the same manner as hereinafter described.

Referring to the single iigure, the embodiment of my invention disclosed herein comprises the usual pneumatic brake operating equipment including brake pipe II, brake cylinder I2, triple valve device I3, auxiliary reservoir I4, brake valve I5, feed valve I6 together with an electrical control mechanism embodied in a casing 30. A bracket or casing section I1, suitably interposed between the triple valve device I3 and the auxiliary reservoir I4 is provided for eiecting the association of the pneumatic equipment and the electrically controlled mechanism in casing 30.

The triple valve device I3 is of the usual construction, having a piston chamber I8 connected to the brake pipe II and containing a piston I9, and a valve chamber containing a main slide valve 2l and a graduating or auxiliary slide valve 22 adapted to be operated by piston I9 through a piston stem 23.

The auxiliary reservoir I4 is open to valve chamber 20 through a passage 24 extending through section I1. Section I1 also contains a double check valve 25, which functions as hereinafter described and comprises a piston 26 operating in a chamber 21 between two opposite positions.

Casing 30 contains a relay valve device 3|, and has secured thereto, preferably by means of threaded extensions, a pair of electro-responsive devices such as the electromagnets and 50.

The electromagnet 40 controls the operation of a double beat valve 4I contained in a valve chamber 42 and the electromagnet 50 controls the operation of a valve 5I contained in a valve chamber 52, for controlling the operation of the relay valve device 3|. i5

The relay valve device 3| comprises a movable abutment, such as the flexible diaphragm 32, having a chamber 33 at one side connected by a passage 34 to the chamber 35 and having a valve 1 chamber 36 at the opposite side containing a re- 10 lease slide valve 31 adapted to be operated by the diaphragm 32 through a stem 38.

A spring 39, disposed between a ange on the stem 38 in engagement with the diaphragm 32 and a shoulder in the casing wall of chamber 36 15 urges the diaphragm toward a position wherein the slide valve 31 uncovers an atmospheric exhaust port 60.

A poppet Valve 6I,V contained in a chamber 62 is disposed in alignment with the diaphragm 20 stem 38 and carries a stem 63 adapted to be engaged by the stem 38 when the diaphragm is moved in a direction to cause the slide valve 31 to cover the exhaust port 60. Such engagement of stem 38 with stem 63 does not take place, how- '25 ever, until after slide valve 31 has entirely closed the exhaust port 6D, as will be explained later. A spring 64, disposed in chamber 62, biases the valve 6I into seating engagement with an annular rib seat 65 separating valve chamber 62 30 from a passage 66 through which stem 63 extends and which opens into valve chamber 36.

The electromagnet 40, when suitably energized, as hereinafter described, actuates a plunger and its stem 43 to cause valve 4I to seat on a valve 35 seat 44 and unseat from an oppositely disposed valve seat 45 against the force of a spring 46 disposed between a collar 41 on the Valve 4I and a wall of chamber 42. The spring 46 is adapted to bias the valve to unseat from valve seat 44 40 and seat on Valve seat 45 when electromagnet 40 is partially or wholly deenergized.

The electromagnet 40 also controls the operation of a circuitbreaker or switch 61 which may be of any suitable construction and which 45 is illustrated as comprising a bell-crank member 68 pivotally mounted on a fulcrum pin 69, which bell-crank member has one arm provided with an insulated contact member 10 adapted to be moved into engagement with another Contact 50 member 1I secured to a stationary supporting bracket 12.

A spring 13, disposed between a shoulder on the supporting bracket 12 and the oppositely extending arm of the bell-crank member is provided for biasing the movable contact member 1I] into engagement with the stationary contact member 1I. Separation of the contact members of switch 61 is effected by electromagnet 4U, when suitably energized as hereinafter explained, by means of a collar 14, suitably secured to an extension of the plunger stem 43, which collar engages and moves the oppositely extending arm of the bellcrank member against the biasing force of spring 13 sulciently to effect separation of the contact members.

The electromagnet 50, when suitably energized as hereinafter explained, actuates a plunger and stem 53 to cause valve 5I to seat on a valve seat 54 against the opposing force of a spring 55, which is disposed between a collar on the'valve 5| and a wall of valve chamber 52 and which biases the valve to unseat from valve seat 54 when electromagnet 50 is deenergized.

The electromagnets 45 and 55 are energized by direct-current supplied from a suitable source, such as a battery 15, through a train wire 16 .which extends through all the cars. The battery 15 is adapted to be connected across the train wire 16 and a ground connection 11 and the electromagnets 40 and 50 on each car are connected across the train wire 'I6 and another ground. connection 18. The connection from the train wire to electromagnet 50, however, is through switch 31 so that energization of electromagnet 53 is controlled by switch 61. A Wire or return conductor additional to train wire 16 may be employed optionally instead ofthe ground return shown.

A brake switch 19, illustrated diagrammatically in developed form, is provided on one of the Cars or on the locomotive and functions both as a voltage control switch and reversing switch in establishing connections between the battery 'I5 and the electromagnets 4I! and 5i), in a manner hereinafter described. In the embodiment shown, brake switch 19 and brake valve I5 are separately operable, the brake valve I5 remaining in .running and release position while the brake switch is operated, and vice versa.

The system is charged with fluid under pressure when the brake valve I5 and the brake switch 19 are in release position, iluid flowing from a main reservoir, not shown, by way of feed valve I6 and brake valveI5 into brake pipe II, whence it flows into the piston chamber I8 of the triple Valve device I3 and causes piston I9 to move into release position as shown in the figure. In this position of the piston I9, fluid under pressure flows from piston chamber I8 to the valve chamber 20 through the usual feed groove around piston I S and from chamber 20 into auxiliary reservoir I4 through passage 24 in the interposed casing section I1.

At the same time fluid under pressure is supplied from passage 24 to chamber 62 containing poppet valve 6I through passage and pipe 82 and passage 83. Fluid under pressure also flows from passage 83 through a branch passage 8s, past a ball check valve 85 and thence through a passage 86 into a storage chamber 81.

If it is desired to effect an electrically controlled service application of the brakes, the brake switch 19 is operated to service position, indicated in the figure, wherein the battery 15 is entirely disconnected from the train wire 16, and the electromagnets 4I] and 50 are both deenerg'ized.

As a result, double beat valve A4I is unseated from valve seat 44 and seated on valve seat 45 while-valve 5I is unseated from its valve seat 54,

thereby establishing a communication for the flow of fluid under pressure from chamber 81 to the diaphragm chamber 33, through passage Sil into valve `chamber 52, past valve 5I, through a restricted opening 9I, passage 92 and past the unseated valve 4I into valve chamber 42, whence the fluid flows through a restricted opening 93 and passage 94 into chamber 35 and thereafter through passage 34 into chamber 33. It will be noted that as fluid under pressure flows from chamber 81, fluid under pressure continues to be supplied thereto from auxiliary reservoir I4 which remains in communication with the brake pipe I I so that the supply of fluid under pressure in chamber 81 is not depleted.

The lluid under pressure supplied to chamber 33 acts on the diaphragm 32 and thus effects movement of the slide valve 31 to a position to close the exhaust port 60, in which position communication between the brake cylinder and atmosphere is cut off, such communication having previously been established by way of pipe and passage 96, double check valve chamber 21, passage and pipe 91, chamber 36 and exhaust port 60 As the movement of the diaphragm 32 continues beyond that necessary to entirely close port 6U, diaphragm stem 38 engages valve stem G3 and causes poppet valve 6I to unseat from rib seat 35, thereby permitting fluid under pressure from the chamber 62 and the auxiliary reservoir I 4 to ilow into the brake cylinder past the unseated valve 6I, through passage 66 into chamber 35, and thence by way of pipe and passage S1, double check valve chamber 21, and passage and pipe 96. Upon such admission of fluid under pressure into the brake cylinder, the piston thereinvis moved to effect an application of the brakes.

The auxiliary reservoir remaining in communication with the brake pipe as previously explained, fluid under pressure is supplied thereto upon venting of fluid therefrom to the brake cylinder, but such supply is at a relatively slow rate with respect to the rate of venting to the brake cylinder, due to the restriction of the feed groove around the triple valve piston I9.

When the pressure of the fluid in the chamber 36 approaches that of the iluid in chamber 33, spring 39 returns the diaphragm 32 to a position wherein its stem 38 disengages stem 63 of the poppet valve 6I, thereby causing the valve 6I to reseat on the rib seat 65 and cut off the further supply of fluid under pressure to the brake cylinder. The movement of the stem 38 is not suflicient, however, to cause the slide valve 31 to crack open the exhaust port 60, due toy the remaining unbalance of fluid pressure effective in chamber 33.

By holding the brake switch 19 in service position a sufficient length of time, the operator permits flow of iluid from chamber 81 to chamber 33 until full equalization of pressure is attained therebetween, in which case the full service application of the brakes is made. The brakes may be held applied by allowing brake switch 13 to remain in the service position or by moving the brake switch to lap position, but after equalization of pressures in chambers 81 and 33 has been attained, the movement of the brake switch to lap position is optional.

If it is desired to apply the brakes to a degree less than that of the full service application or if it is desired to apply the brakes in a series of steps or graduations, the brake switch is rst moved to service position and held there only long ISO 'Cil

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enough to eifect a desired degree of brake application, after which the brake switch is moved to lap position.

When the brake switch 19 is in lap position, electromagnet 59 is energized to cause valve 5| to seat on valve seat 54 and thus close the communication for the supply of iluid under pressure from chamber 81 to chamber 33. The circuit for energizing electromagnet 50 extends from the positive terminal of battery 15 to the ground connection 11 by way of conductors |0| and |92, contact member |03 of brake switch 19, and conductor |04, and thence from ground connection 13 through conductors |05 and |06, electromagnet 50, conductor |01, switch E1, conductor |98, train wire 1G, conductor |09, contact member of brake switch 19, and conductor ||2 to the central negative terminal of the battery 15.

It will thus be noted that a reduced or relatively low voltage is impressed across the train wire and ground. Electromagnets 40 and 50 are so designed that the latter only is operatively responsive to this low voltage, the former being ineifectually energized. Thus switch 61 remains closed and enables the continued energization of electromagnet 50.

The continued energization of electromagnet 50 eiects the movement of valve 5| to seat on valve seat 54, thereby cutting off the communication for the supply of iluid under pressure to diaphragm chamber 33, as above pointed out.

The approach of equalization in fluid pressures in chambers 33 and 36 on opposite sides of diaphragm 32 effects substantially immediate return movement of diaphragm 32 to close valve 6| to cut off further supply of fluid under pressure from the auxiliary, reservoir to the brake cylinder but not suicient movement to cause the slide valve 31 to crack open the exhaust port B0. Thus the fluid pressure is maintained in the brake cylinder and the brakes are held applied in the degree desired.

Successive steps to increase the degree of application of the brakes are eected, as above described, by repeated movements of the brake switch to service position and then return movement to lap position.

It should be here noted that the function of restricted opening 9| is to so restrict the passage of uid from chamber 81 to chamber 33 that an appreciable time is required to eiect full Iequalization of pressures in the two chambers. Thus by movement of the brake switch to lap position prior to full equalization of pressures in chambers 81 and 33, a partial application o'f the brakes may be eifected.

If it is desired to electrically effect the release of the brakes after an electrically eected application thereof, the brake switch is moved to release and running position, that is, normal position. In this position of the brake switch, the entire voltage of battery 15, that is a relatively high voltage is impressed across the train wire 16 and the ground connection, and electromagnet 40, which is operatively responsive only to this high voltage is thus energized. The circuit for energizing electromagnet 40 extends from the positive terminal of battery 15, through conductor lill, contact member ||3 of brake switch 19, conductor |09, train wire 16, conductors 68 and H4, electromagnet 40, and conductors |95 and |05 to the ground connection 18, and thereafter from the ground connection 11 through conductor |04, contact member of brake switch 19 and conductor |l0 to the end negative terminal of battery 15.

Upon the effective energization of electromagnet 40, as above described, switch 61 is opened and thus the parallel branch circuit from ground connection 18 to conductor |08, which branch circuit includes electromagnet 50 and switch 61, is immediately opened and electromagnet 50 is not energized except perhaps for a momentary impulse before switch 61 opens. This momentary impulse is, however, ineective to cause valve 5| to be maintained in closed position, in which position it was maintained by the energization of electromagnet 50 at low voltage, while brake switch 19 was held in lap position.

It will be noted that the polarity of the connections of the battery to the train wire and ground connection is reversed from that when the brake switch 19 is in lap position. The purpose of the reversal of polarity is to ensure proper action of the plungers of the electromagnets 40 and 50 without sticking. Thus the momentary impulse applied to electromagnet 50 is effective to break down any magnetic flux remanence in the field core structure thereof and the energization of electromagnet 40 is effective to first break down any magnetic flux remanence in the eld core structure thereof and subsequently to set up a field flux in the opposite direction to positively actuate the plunger and stem 43 to move the valve 4| to seating position on valve seat 44 and unseat it from its seat 45.

'I'he seating of valve 4| on its valve seat takes place at the same time that valve 5| is unseated from valve seat 54. Thus the point of cut-off in the communication between chamber 81 and chamber 33 is changed but in such manner as to prevent an undesired reapplication of the brakes.

With the valve 4| unseated from its seat 45, communication between diaphragm chamber 33 and atmosphere is established by way of passage 34, chamber 35, passage 94, restricted opening 93, chamber 42, past valve 4|, passage ||6, and exhaust passages ||1, and chamber 33 is vented.

As the iiuid pressure in chamber 33 decreases below the fluid pressure in chamber 36, the diaphragm is moved in a direction to cause slide valve 31 to open the exhaust port 60, thereby effecting the exhaust of iluid under pressure from the brake cylinder by way of pipe and passage 93, double check valve chamber 21, passage and pipe 91, chamber 36, and port 60, and resulting in the release of the brakes.

If complete release of the brakes is desired, the brake switch is left in the running and release position so that complete venting of chamber 33 occurs, in which case spring 39 returns the diaphragm 32 to the position shown in the ligure.

If only a partial release of the brakes or release of the brakes in a series of steps or graduations is desired, the brake switch is rst moved to release position and held there only long enough to secure the desired degree of release, after which it is moved to lap position, wherein the valve 4| is seated on its valve seat 45 to cut off further release of uid under pressure the exhaust of fluid under pressure from chamber 33 so that partial or graduated release of the brakes may be effected. The opening 93 is slightly larger than the restricted opening 9|, so that the latter primarily controls the timing of the admission of fluid under pressure to chamber 33 from chamber 81, as described above for a service application effected electrically.

In the event that it is desired to operate the brakes pneumatically without resorting to the electrical control above described, the brake switch 'i9 being in release and running position, the brake valve I is moved to service position, as indicated in the figure, wherein a reduction of fluid pressure in the brake pipe Il through exhaust port I Il of the brake valve I5 effects a corresponding reduction in the fluid pressure in piston chamber I8 of the triple valve device I3. The excess of pressure in valve chamber 20 is thus effective to move the piston I9 to service position in the usual manner, in which position the auxiliary slide valve 22 uncovers the service port I I8 in the main slide valve 2|, and the main slide valve 2| is in such position that the service port II 3 therein registers with brake cylinder passage H9 leading from the seat of the main slide Valve to the double check valve chamber 2l, while the brake cylinder exhaust port or passage |25 opening at the seat of the main slide valve is lapped.

Fluid under pressure is thus supplied from auxiliary reservoir I4 to brake cylinder I2 through passage 24, chamber 20, service port IIS, passage H9, valve chamber 27, branch passage I2I and passage and pipe 96. It will be understood that'when piston 26 of the double check valve device 25 is subjected to iluid under pressure from passage H9, it is moved to establish communication from passage H9 to passage |2| and simultaneously to cut 01T the connection to atmosphere from the brake cylinder through port 55 by closing the communication between passage 95 and passage 91.

Upon substantial equalization of pressures in valve chamber 25 and piston chamber I8, the piston I9 is moved to cause the auxiliary slide valve 22 to lap the service port ||8 in the main slide valve 2| and thus cut olf the further supply of fluid under pressure from the auxiliary reservoir to the brake cylinder. The exhaust passage |25 remaining lapped by the main slide valve 2| the iluid under pressure in the brake cylinder is retained therein, thus maintaining the brakes applied.

'I'o eifect a release of the brakes pneumatically after an application is effected pneumatically, the brake valve I5 is moved to running and release position wherein the brake pipe pressure is increased by connection of the brake pipe I I to a main reservoir, not shown, through the brake valve I5 and feed valve I6. 'I'he corresponding increase in fluid pressure in piston chamber I8 moves the piston I9 and slide valve 2| to release position shown in the figure, wherein brake cylinder passage I I9 is connected to exhaust passage |29 through cavity |22 in the main slide valve 2 I. 'I'hus fluid under pressure is exhausted from the brake cylinder and the brakes are released.

Operation of the brake valve I5 to lap position prior to full application or full release being obtained enables a partial or graduated application and partial or graduated release in the usual manner.

Emergency application of the brakes is effected pneumaticallv bv movement of the brake valve I5 to emergency position which results in such a rate of reduction in fluid pressure in pist0n chamber I8 as to cause sufficient movement of the slide valve 2| to effect registration of the emergency port |23 with brake cylinder passage H9.r The emergency po-rt |23 being larger in cross-sectional area than service port ||8 permits a faster rate of flow of fluid under pressure from the auxiliary reservoir to the brake cylinder so that an emergency application of the brakes is effected.

It will thus be seen that I have provided a braking system wherein separately operable control means are provided for eiTecting the operation of the brakes pneumatically and electrically. It will be seen, further, that I have provided means including a pair of electromagnets, operatively energized at different voltages of opposite polarity, and a switch controlled by one of the electromagnets for controlling the energization of the other electromagnet, whereby the operation and control of the brakes may be eifected electrically.

It will be understood that while one specific embodiment has been disclosed, my invention is capable of various changes, omissions and additions, without departing from the spirit thereof. For example the electrical control portion of my invention may be employed to control electro-responsive brake operating means instead of pneumatic means as illustrated.

t is not my intention, therefore, to be restricted in the scope of my invention except as necessitated by the prior art and as defined in the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In an electrically controlled brake, in combination, two electro-responsive devices for effecting the operation of the brakes, means for impressing a relatively high voltage and a relatively low voltage on said electro-responsive devices, one of said electro-responsive devices being inherently adapted to be operatively responsive to the said relatively low voltage and the other being inherently adapted to be operatively unresponsive to said relatively low voltage, and circuit-controlling means effective upon the impression of the said relatively high voltage on said electro-responsive devices to prevent an operative response of said one electro-responsive device thereto.

2. In an electrically controlled brake, the combination of a pair of electrically controlled means for effecting the operation of the brakes, one of said electrically controlled means being operatively responsive to a voltage higher than a predetermined voltage and the other being operatively responsive only to a Voltage higher than a second predetermined voltage higher than said rst predetermined voltage, and means effective when a voltage higher than said second predetermined voltage is impressed on said pair of electrically controlled means for preventing an operative response thereto of the said one electrically controlled means.

3. In an electrically controlled brake, the combination of a` pair of electrically controlled means for effecting the operation of the brakes, one oi said electrically controlled means being operatively responsive to a voltage higher than a predetermined voltage and the other being operatively responsive only to a voltage higher than a second predetermined voltage higher than said rst predetermined Voltage, and circuit controlling means operated by the other of said electrically controlled devices to prevent the imposition of voltage on the said one electrically controlled means when a voltage higher than said second predetermined voltage is impressed on the other of said electrically controlled means.

4. In an electrically controlled brake, in combination, a pair of electroresponsive devices for controlling the operation oi the brakes, one of said devices being operatively responsive to voltages higher than a predetermined voltage and the other of said devices being operatively responsive only to voltages higher than a second predetermined voltage which is higher than said rst predetermined voltage, means for imposing the said voltages on said devices, and means effective upon the imposition of a voltage higher than the said second predetermined voltage on the other of said devices for preventing the operative response of said one device to that voltage.

5. In an electrically controlled brake, in combination, a pair of electroresponsive devices, one of which is operatively energized by a certain voltage and the other of which is non-operatively energized by said certain voltage and operatively energized only by a predetermined voltage higher than the said certain voltage; means for imposing the said voltages on said devices, means for preventing the operative energization of said one device upon the operative energization of the other of said devices, and means controlled by said devices for eiecting application of the brakes upon deenergization of both said devices, for effecting release of the brakes upon operative energization of the other of said devices, and for holding the brakes applied upon the operative energization of the said one of the devices.

6. In an electropneumatic brake, in combination, a primary electrically controlled means operative upon deenergization to establish cornmunication through Which uid under pressure is supplied to effect an application of the brakes, a secondary electrically controlled means operative upon energization to close said communication, means for supplying energizing current through a commen train Wire to both electrically controlled means, and means for interrupting the supply of current to the secondary electrically controlled means upon energization of the primary electrically controlled means.

7. In an electropneumatic brake, in combination, a primary electrically controlled means operative upon deenergization to establish communication through which uid under pressure is supplied to eiect an application of the brakes, a secondary electrically controlled means operative upon energization to close said communication, means for Supplying energizing current through a common train Wire to both electrically controlled means, means for opening the circuit to said secondary means upon energization of the primary means and for closing the circuit upon de-energization of the primary means, the secondary means being operatively energizable at a lower voltage than the primary means.

RICHARD L. NASH. 

